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Pursuvant

OEM fork parts - too much/too fast wear XSR700

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Pursuvant
Posted (edited)

-----2019 XSR700 report ------

Ohlins service shop was in my bike's front forks to do annual service this off-season (extends NIX-22 & STX-46 warranty) and they found some OEM fork parts that are showing a lot of wear, considering one season of riding & mileage (22K). Parts are the fork spindles & metal slides - they are teflon impregnated, look like they are "wearing" too fast (shop's description not mine). Yes I ride alot in a year and I like my killer brakes.

Parts (#11,#31 Spindle, Taper and #9,#29 Metal, Slide. I checked out the parts, heavy wear/worn thru teflon. Somehow to me, it feels like exactly what I should expect. They ordered replacement parts from Race Tech, and next year I will be checking my notes and we will be looking at these aftermarket parts to see how they worked out.
 

pzillaforks.jpg.b12435030c283512b4183e688aeb845d.jpg

Edited by Pursuvant
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Triple Jim
Posted (edited)

Great post, thanks.  I'm not sure I understand all the double numbers though, like "11,31".  Is this drawing for two different parts lists?

Edited by Triple Jim

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twf

It is common practice to remove 11,31 part. It is plastic piece and will do same in short time. It expends and gets tight in tube. It is hydraulic lock to protect metal to metal contact on full compression.

Teflon wearing is also common on this forks, there is thread about it. I believe it is due to tolerance between tubes.  

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Lone Wolf
5 minutes ago, twf said:

...Teflon wearing is also common on this forks, there is thread about it. I believe it is due to tolerance between tubes.  

Is that this one about the bushings? 

 

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twf

Yes. 

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cornerslider
11 hours ago, Triple Jim said:

Great post, thanks.  I'm not sure I understand all the double numbers though, like "11,31".  Is this drawing for two different parts lists?

Yamaha calls out "double numbers" on forks. One for the right leg, and one for the left leg. Seems a little silly to me-

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""W.O.T. until you see god, then brake"

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Pursuvant

My slides below, 22K miles. They have already been replaced with RaceTech aftermarket (that will be looked at next off season to see how they performed). I did not go with AllBallsRacing as was suggested in this post from 2015.

img1.jpg.b28667067d89d311acd69a232a879bff.jpg

img2.jpg.87b3b00752dc95bfb67dac29c3613b1d.jpg

img3.jpg.c6db2af8bebf141f8f0fb43b6ee9f411.jpg

img4.jpg.44e961edf348e603d5e0f62eec0ec06d.jpg

 

Thank you @clinical for posting this last post (page 12) of this post I copied the post pic from there and show it below.

clinical1.thumb.jpg.b71cc3fec4c6bd632bea61667fc173bf.jpg

The suggestion was the end ring "gap" so to speak, should be 1mm, not 5mm (like the worn slides above).

That idea had a counter-idea that our friend @twf demonstrated evidence about on page 9 of that post, I copied his ideas into the below

From  @twf -------

Yes, something is going on and I think I know what it is. Bottom line is I am not finding any of things mentioned here.
- Bushing with gap is not incorrect bushing used by factory as stated. Gap is there by design. Incorrect bushing is the one without gap.
- I am not measuring them out of the round
- I am also not measuring them at 41.1mm as mentioned in first post, 1.653 = 42mm.
- They do spin around, look at picture of cut out tube I posted, at 8 o'clock you can see multiple lines going up/down the tube. That is bushing gap rotating. 
- Outer tube I have here is not out of the round

-------

Neither of these competing ideas seamed to ever be accepted as the answer from that 2015 post (it just went dead), but it may not matter to my slides, when you compare the wear patterns. All the pics I saw from that 2015 post, they were worn as badly as mine, yes, but they were uniformly worn, the entire slide had the same amount of wear.

My slides have a distinct pattern, the photos of my slides show a pattern where the teflon has normal wear on about 240 degrees of slide. The pattern where complete teflon wear appears on only about 120 degrees of the slides. I have an idea what the answer to my wear issues are, but I would like to see what you all think of my wear pattern.

 

 

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Triple Jim

How thick was the original Teflon coating?  I'm not seeing much wear of the metal under the Teflon.  Even in the  most worn spots I can still see a little of the original roughness.  It looks a lot like the coating on 2-stroke pistons that mostly wears off in the first couple hundred miles, and is really just there for break-in.

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clinical
Posted (edited)

@Pursuvant wow those were toast!  Good thing you changed them.

One theory that I believe explains the wear on mine (and, I believe yours as well) that was proposed by @pattonme : since the bushing is too small it becomes oval to fit around the oversized tube.  So now you have a scenario of a oval bushing in a round hole.  Where the bushing actually wears most is probably variable depending how it happened to bend to fit around the fork tube, but in most cases I'd bet the parts of the bushing closer to the notch will bend more (because the main point of flex is 180* from the notch so the further away you travel further off tolerances will be)

@Triple Jim For these bushings its recommended to replace when Teflon wears away.  If you take a look at a new bushing the coating is quite thick, not just for wear in.

 

Edited by clinical
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Lone Wolf
Posted (edited)

Just for a rough comparison, I just took the forks apart on an old 1993 Honda 750 Nighthawk to replace the leaking seals.

33,000 miles on the bike and the upper and lower bushings appeared like new. I could see wear marks on the Teflon, but no where was it down to the metal. I was kind of shocked how good they still looked.

Note the tight gap in upper bushing (comes out when separate lower leg)

Also very tight gap in lower bushing that is at bottom of fork stanchion

Upper NH bushing.jpg

Lower NH bushing.jpg

Edited by Lone Wolf
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Lone Wolf
Posted (edited)
1 hour ago, Lone Wolf said:

Just for a rough comparison, I just took the forks apart on an old 1993 Honda 750 Nighthawk to replace the leaking seals.

33,000 miles on the bike and the upper and lower bushings appeared like new.

Compare to member fzar lower bushings with 26,000 miles from page 12 of this thread

FZAR lower.jpg

In the first post of that old (huge) thread, pattonme blamed Kayaba (KYB) not Yamaha.

Edited by Lone Wolf

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twf
6 hours ago, Lone Wolf said:

Just for a rough comparison, I just took the forks apart on an old 1993 Honda 750 Nighthawk to replace the leaking seals.

33,000 miles on the bike and the upper and lower bushings appeared like new. I could see wear marks on the Teflon, but no where was it down to the metal. I was kind of shocked how good they still looked.

Note the tight gap in upper bushing (comes out when separate lower leg)

Also very tight gap in lower bushing that is at bottom of fork stanchion

Upper NH bushing.jpg

Lower NH bushing.jpg

Different design. All upper ones are tight gap. Lower ones depends on design. Tubes with holes like the one you pictured use tight gap. Tubes without hole use wide gap, that gap has same purpose as hole to get oil in that space above bushing. Many bikes have wide gap design, none is wearing bushings as fast that I have seen.  

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Lone Wolf
29 minutes ago, twf said:

...Tubes without hole use wide gap, that gap has same purpose as hole to get oil in that space above bushing. Many bikes have wide gap design, none is wearing bushings as fast that I have seen.  

Interesting. Yeah my amazement was the lack of wear on 33,000 mile bushings. That Honda fork was made by Showa.

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ElGonzales

Because of all this stories I used the last x-mas holidays and took a look at my 2014 MT-07 fork at 23.000 km.  All the upper and lower bushings were fine (wanted to change oil and springs anyway). The coating was all around in good condition. Even the oil looked like new.  But I replaced the bushings and seals with All Balls Racing parts ( no. 56-129 and 38-6095), I compared and measured them to the original ones and saw no  differences that would give me worries. 

Top is original Yamaha, bottom ABR

bushings1.thumb.jpg.4e081c70d67b79d7425141ebd430c548.jpg

 

Gap of original Yamaha bushing

PXL_20201114_123828027_noexif.thumb.jpg.870fdf037ef9d81de7eb542fb1c0faca.jpg

 

Yamaha left side, All Balls right side

PXL_20201114_130010287_noexif.thumb.jpg.62149caf034687d757eda5d25c8e8c58.jpg

The whole service was quite unnecessary, there wasn't even a notable amount of abrasion or dirty areas to clean inside the fork. But I like to play around and do things in the winter time without time pressure.

The fork moves very smooth ... as it did before, but now with new progressive springs. And one new thing: it sinks down some millimeters if I just sit sown on the bike.
I kept the old parts in my spare parts box, in case there is trouble with the new stuff :)

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Pursuvant
Posted (edited)
16 hours ago, ElGonzales said:

Because of all this stories I used the last x-mas holidays and took a look at my 2014 MT-07 fork at 23.000 km.  All the upper and lower bushings were fine (wanted to change oil and springs anyway). The coating was all around in good condition. Even the oil looked like new.  But I replaced the bushings and seals with All Balls Racing parts ( no. 56-129 and 38-6095), I compared and measured them to the original ones and saw no  differences that would give me worries. 

Top is original Yamaha, bottom ABR

bushings1.thumb.jpg.4e081c70d67b79d7425141ebd430c548.jpg

 

Gap of original Yamaha bushing

PXL_20201114_123828027_noexif.thumb.jpg.870fdf037ef9d81de7eb542fb1c0faca.jpg

 

Yamaha left side, All Balls right side

PXL_20201114_130010287_noexif.thumb.jpg.62149caf034687d757eda5d25c8e8c58.jpg

The whole service was quite unnecessary, there wasn't even a notable amount of abrasion or dirty areas to clean inside the fork. But I like to play around and do things in the winter time without time pressure.

The fork moves very smooth ... as it did before, but now with new progressive springs. And one new thing: it sinks down some millimeters if I just sit sown on the bike.
I kept the old parts in my spare parts box, in case there is trouble with the new stuff :)

Great post @ElGonzales

This is why I think  @twf nailed it, thank you sir, with no disrespect to @pattonme.

It could also be just lousy teflon, or some other ?. No matter which ideas you suspect, good course of action is get them replaced. Next year I will know if RaceTech works or not. Till then, kick azz with my nx-22 and Brembo rcs17 corsa corta

Edited by Pursuvant
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ElGonzales
Posted (edited)

In this area of the fork very small distances of 1/10 mm or less in any of the dimensions of a part can cause the difference between: it works (but wears fast) and it works great over he long distance. I think we all know that.

What I find noticeable is the shape of the wear in this picture:
bushing2.jpg.693d6293fd62ad61e2215b012af5174a.jpg

bushing2b.jpg.04fbb5538855bd00a6efce4154f82a39.jpg

Isn't the worn out spot supposed to cover the complete high of the bushing? The blue marked areas still have teflon coating. Would this image fit to the "oval bent" theory?

Maybe in production of the bushing, they cut one long tube into many pieces and bent the edges a tiny bit to the inside, so there is an decreased contact to the outer tube?  😕

 

Edited by ElGonzales

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Triple Jim
2 hours ago, ElGonzales said:

Maybe in production of the bushing, they cut one long tube into many pieces and bent the edges a tiny bit to the inside, so there is an decreased contact to the outer tube?

That's what it looks like to me.  Best not to have the edges hitting hard, I'd think.

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Pursuvant
Posted (edited)

I erased the whole thing about it being my braking. A friend woke me from that illusion - forks can handle what throw at 'em

Edited by Pursuvant
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Lone Wolf
Posted (edited)
1 hour ago, Pursuvant said:

I think this wear is entirely the result of the extreme braking I do all the time...

I don't think you are harming the bushings with extreme braking.
The fork oil does its job, protecting parts just like all the other wearable parts (connecting rod bearings, pistons against cylinder, etc.)

If anything you are helping the spirit - 4 wheels move the body. 2 wheels move the soul.

The general public thinks motorcycles are dangerous. I think living a boring life is dangerous, none of these bodies lasts forever. Superman broke his neck falling off a horse, Bruce Lee had allergic reaction to a med. May as well ride a motorcycle and pile on the miles as you have done. That is awesome.

But others have seen similar wear, like member @fzar at 26,000 miles, and @ElGonzales photos above.

FZAR lower crop.jpg

Notice how perfect my old Honda Nighthawk lower bushings are on prior post. I threshold brake that bike all the time (maybe not as much as you) because I want confidence that the EBC HH pads and braided lines are helping the awful 1993 single disc brake on that bike. 33,000 miles with an abundance of threshold braking and I could see no wear on the Teflon.

Edited by Lone Wolf
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